Wednesday, November 28, 2012

Alien Tutorial

I've mentioned the alien tutorial a few times but I haven't actually written properly about it, so I'll do that now.

In order to grasp the techniques involved with modelling, UV mapping, binding, rigging and finally animating a biped model, we spent a number of weeks following a tutorial along with our tutor to create an alien character, with the intention of creating an animated character turntable of him/it in Unity.

Sadly I haven't taken many screenshots during the process, but you can see here that we made a control rig for the body and also one to control basic facial expressions. We've learnt, in more depth, about a wide range of tools in Maya, including the joint tool, weight painting tool, contraints and control/joint hierarchies and making the controls themselves from NURBS shapes and curves.

I've really enjoyed the whole tutorial as I've been keen to learn more about creating characters in more technical detail, as it's possibly the main area of animation I'm interested in.

A few key ideas I've learnt through this that I will take forward into future projects include:

- When modelling, it is vital to pay close attention to the topology and edge flow of the character you're creating. Generally you want your edges to follow the shape of the geometry and show how it will move, and not be all over the place, as it'll be crucial when it comes to animating. You also want to model using exclusively square shapes (in my model there are a few accidental triangles, but as it's very simple it doesn't effect it too much. I will be careful of this on more detailed projects).

This is of particular importance in the face, as illustrated below. Compare the topology around the eyes and mouth:

The "good" edge flow almost mimics the muscle structure of a real face, so that when the character pulls faces the rest of the face will move in a realistic way.

- When building the skeleton using the joint tool, limbs such as the arms and legs should be kept straight and posed far away from each other (like a T-pose). This is so that when it comes to weight painting it's easier to control the influence that a joint has on surrounding joints - if the arms are placed close to the sides, for instance, you will get influence from the arm joints effecting the torso, and a lot of time will be spent making sure there is no influence in these unwanted places. 

- On the arms, an extra joint should be added to the forearm which allows the forearm to rotate slightly when the wrist does, which is more realistic (otherwise the wrist rotates too sharply and can collapse inwards). 

- Set Driven Keys (SDK's) are custom attributes that are added to allow easy manipulation of more in-depth movement without having to move the joints themselves. Generally to create these you:
- Add a custom attribute to the controller of the area (e.g. the hand controller)
- Group the joints that you want effected together in the Outliner
- Edit the group's pivot point to reflect which direction the joints should move
- Open the Set Driven Keys window within the attribute editor
- In the window, load the driver of the attribute (the control), and the joints effecting the driven attribute 
- Set the custom attribute to 0, and place the joints in the position you want, and hit the Key button
- Set the custom attribute to 10, place the joints in the position you want, and hit the Key button.
These attributes are very useful for controlling hands and feet where there might be a lot of joints and intricate movement . 


Here's the final turnaround for my alien, which showcases my model and his walk cycle (I decided for no real reason to give him a swagger), idle animation and jump animation. I wanted to edit them further using the animation graph, but I couldn't figure out which parts to edit - they could all use some further tweaking as the movements look a bit "floaty", but until I get my head around the graph editor, I'll have to leave it as it is.

Unity Web Player | WebPlayer

Binding & Rigging

Tabitha is almost ready to be animated! 

Here is the rig I've built for her. It mostly follows the basics of what we learned during our alien tutorial, but this character had a few unique challenges we've had to overcome, the most obvious one being her skirt. After adding in joint chains at the front, sides and rear of the skirt, I first attempted to rig it and control it by manipulating individual joints, but this proved to be very difficult to define with weight-painting and it didn't offer very natural skirt-like movements.

So I've gone for single-chain IK handles instead. Although these offer less control over the smaller movements of the skirt, when I briefly tested it it seemed much easier to animate to move along with the legs. She will be fairly limited in her movement, for example if she were to kneel on the floor it might prove difficult to realistically have the skirt move with that, so I think we'll have to ensure we avoid using extreme poses and use clever camera angles to disguise shots where the skirt might go awry. 

I created some *very quick* playblasts to see how the skirt might move. Obviously her actual animations will be much more detailed and interesting - it was just to get an idea of how the IK handles work practically. It seems to be fine - I scaled the skirt out at the back as she walked to give the impression of it dragging along the floor, and the front section scales outwards as her knee moves forward to take a step. 

I came across another problem whilst creating custom attributes and SDKs for areas such as her ankles and feet. Because her feet are so small, the edge flow doesn't follow a natural foot shape, and so when I tried to set up SDKs to allow the animator to manipulate the peel heel/toe tap/twist heel attributes to create more lifelike walk animations, the result... wasn't so lifelike.

I tried to fix it by altering the weight painting, but I think this issue is beyond repair simply because of the way I've modelled her, so I've had to scrap all the SDKs on the feet. I've still added them to the hand so that she can clench her fist and move her fingers.

Saturday, November 17, 2012

Development of my model

Some shots of the development of the model for Tabitha, the character I'm creating for my group machinima project.

This has been my first try (outside of the tutorial) at making a model in preparation for rigging and animation. I've made a couple of silly mistakes, including making the model as a whole rather than just building one half and mirroring, meaning that she isn't quite symmetrical. I also didn't pose her with her arms and legs completely straight, though I think I'll be able to overcome this when rigging by just being careful with where I place the joints. 

Originally the skirt was going to be a solid piece of geometry with her feet sticking out at the bottom, but I found this awkward to model so I just decided to construct her full figure and add the skirt on top. This'll also mean we can rig the skirt separately to the legs and animate it, which I think will make her movement a lot more dynamic and interesting.

Seeing as we are going for a charming, cartoony style her facial features are going to be flat and part of the texture, not modelled into the geometry. 

Her hair has been the most awkward part of the process, and I had to delete and re-model the geometry for the fringe pieces as for some reason faces were missing where the vertices met her head. Although I still need to smooth the model, I think I'm finally at a stage now where I can focus on the UV mapping, and then the rigging. 

Bradford Animation Festival

Last week I spent a few days at Bradford Animation Festival with the course. Last year we went to BAF Game, which focusses on video game art and design rather than animated films, so I was curious to see what the main festival was like. Most of my time there was spent watching short films, although to be perfectly honest I often struggle to become engaged by "artsy" short animated films so there were only a handful I could say I really liked.

One of these can be seen at the following link:

The main thing that struck me about this was that it was one of the few that appears to use computer-generated 3D animation techniques. The scenery and surroundings are illustrative and 2D, and the textures of the characters themselves have a cel-shaded look, which overall gives the film a unique and charming appearance, although the mood and narrative is quite dark.


There was also a panel discussing the importance of student films (as opposed to showreels) and how they can play a crucial part in defining the future of your career. The speakers included Tony Prosser, who established RealtimeUK, Caroline Parsons, a senior lecturer at Newport, Chris Williams, Dean of Computer Animation at Bournemouth University and Sophie Jenkins, Recruitment Manager at Double Negative.

A general opinion shared across the panel was that a short film should advertise the student's design ethic and attitude, and also demonstrate that the student has the drive, ambition and dedication to succeed within the industry. There were some differing views regarding creativity and imagination; Caroline Parsons, who values creativity above technical prowess, expressed how an ability to create characters and stories that have a real, emotional impact on an audience is key; how the student chooses to express that, whether in more simplistic animation methods or something more technical and involved, is irrelevant. Sophie Jenkins of Double Negative and Tony Prosser of RealtimeUK opposed this by saying a demonstration of excellent technical abilities was more important for their particular companies (which is expected of VFX companies - I suppose it is all dependant on where the student wishes to end up working). Another key asset is to have a specialist skill, but also a good range of generalist knowledge, and to have a broad scope of interests which feeds into your work.

Interestingly, members of the panel said that student film standards have been going down, and animation courses have been "losing their way", particularly in the UK where the courses are a couple of years shorter than those in other countries in Europe. Students are lacking creative awareness, and can even become delusional about their creative and technical abilities, because their scopes are often so narrow.

These industries are highly competitive and demand high levels of technical skill as well as creativity and intelligence. Thousands of people can apply for these positions but only the ones who demonstrate genuine talent will get jobs. It might have been seen as being fairly blunt and harsh for the panel to say this, but I appreciate their honesty - hearing this sort of advice is a really important part of developing and evolving as an artist.


Unfortunately this year BAF Game had a handful of exciting guests that I missed as I couldn't afford to attend both sides of the festival. These included Tomek Zawade of CD Projekt Red, the studio behind The Witcher and The Witcher 2: Assassins of Kings, giving a presentation about choosing between the movie and games industries, Lucas Hardi of Bethesda talking about the history of art style within games, and Neil Thompson who is currently an art director at Bioware.

I ended up spending extra money on going to see Neil Thompson, given my recent love for Bioware's games. He gave a detailed overview of his career from creating artwork for Spectrum and Commodore 64 games, to working for Psygnosis at the dawn of 3D game software, through to working on the Wipeout franchise and Blur, and finally Dragon Age and Mass Effect 3. He repeated the advice of previous speakers at the festival: that an aspiring artist should take their influence from everywhere, and particularly become interested in art history. Being a game artist who only plays games means that everything you create has already been done in some way - but being inspired by history, architecture, nature, art, films, and the general world will produce fresher ideas and concepts.
(I was looking forward to hearing about his work at Bioware, but unfortunately he didn't really talk about that, or about his actual work as an illustrator and artist - but it was still very interesting).